Engine blowby gases, sometimes referred to as crankcase ventilation gases, comprise engine crankcase off gases with particulate material (typically both solid and liquid) therein. It is desirable to filter these gases, for a reduction in contaminant levels. A variety of arrangements for conducting such filtrations are described, for example, in U.S. Pat. Nos. 5,853,439; 7,081,145; 6,143,049; 6,530,969; 7,182,804; WO 2005/082488, published Sep. 9, 2005; WO 2006/084282, published Aug. 10, 2006; PCT WO 2005/083240, published Sep. 9, 2005; WO 2007/053411, published May 10, 2007; and WO 2006/091594, published Aug. 31, 2006, each of which is incorporated herein by reference, in its entirety.
In general, improvements have been sought, to accommodate different types of arrangements.